diamond geezer

Monday, February 10, 2014

I've never previously been on a tour of a Sainsbury's car park. But then very few Sainsbury's car parks have something this unusual hidden within. The big store in Whitechapel used to have a fairly standard car park, a large open space in an otherwise fairly-built-up corner of the East End. So when Crossrail came along several years ago and started making plans, they coveted Sainsbury's car park and proposed using half of it as a worksite. A brand new temporary multi-storey was constructed on the other half, because people drive to the shops even in Tower Hamlets. And then Crossrail moved in to dig an extremely big hole where previous there'd been cars and trolleys. I doubt that most of the current shoppers have even noticed.

Crossrail stations are very long. They need to be because Crossrailtrains are very long, and the platforms need to be even longer in case those trains are ever extended. That puts the eastern end of Whitechapelstation under Sainsbury's car park, near Cambridge Heath Road, 250 metres away from the main station entrance. Best get off at the right end of the train in 2018, else it's going to be a long walk. The Cambridge Heath shaft is a key part of the construction of the new station, and will house emergency evacuation routes and tunnel ventilation when the railway finally enters operation. The cylindrical hole is 30 metres wide and 35 metres deep, which is pretty damned massive, although par for the course along Crossrail's underground tunnelling route. And a few of us got to look down it yesterday.

Not many of us, as it turned out. Tours were only announced three days in advance, rather than weeks, and not in a very obvious way. Barely half a dozen tours of Whitechapel were scheduled, which isn't many. And when we turned up yesterday each tour was for only about ten people, which smacked somewhat of Crossrail undertaking a community engagement box-ticking exercise. But there was actually a reason why so few of us got in, which is that the space available inside was rather small. And no, we weren't allowed down to platform level, but we still had to tog up in safety garb - that's hi-vis tabard, branded helmet, plastic specs and disposable gloves. I looked damned stupid, but thirty seconds after walking into the "acoustic shed" I was glad I was wearing them.

Whitechapel's acoustic shed exists to protect local residents from noise. A lot of racket is being made down at platform level, and in the shaft, and above it, so some sort of metal covering is essential to prevent unnecessary decibels from leaking out. Enter within this dark enclosed space and an entirely alien environment assaults you. Way overhead is a huge crane, of the "along" kind rather than the "up", plus several thick pipes venting up from below. The crane leads off to one side, with a sheet concealing something behind. And then there's a vast hole, carefully fenced off, leading down into the earth. A temporary metal staircase zigzags down from the rim, up which workmen occasionally emerge, and alongside is a truck-mounted crane dangling a line over the edge. With a few tweaks this could have been a Hollywood film set, perhaps of a drilling operation at the mouth of hell, but instead all was professional and secure.

We were led to the far side of the shaft to stand on a narrow metal platform. That's a narrow metal platform suspended above a 30 metre drop, so not ideal for anyone ill at ease with heights. Peering through the grille we could look down to platform level below, or at least a circular workspace that may be one day be a concourse. The overriding colour was grey, which is perhaps not surprising given that station construction involves drilling through London Clay and then spraying it with concrete. Something was coming up on the end of the smaller crane's line, which turned out to a cage of people, because presumably yomping up the staircase gets a bit tiring over and over. Then when they were out of the way the sirens went, and the crane overhead swung into action, and flapping cables suggested that something more substantial was on the move.

All that earth dug out beneath Whitechapel has to go somewhere. Below ground trucks shift it to the bottom of the shaft, then tip up to pour the spoil into a giant skip. When this is full it's raised by the crane, hence the flapping cables, and at some considerable speed. We watched as the skip passed within a couple of feet of us, praising the crane driver's manoeuvring skills, then rose to the ceiling some distance above. At the top the direction of travel switched to horizontal, slowly disappearing beyond the sheet to the east, where we were told it would be stored along with the rest of the day's debris. Lorries then turn up during carefully agreed hours, weekday daytimes only, and drive to Crossrail's unloading point on the Thames for a boat trip to Essex. The ultimate destination is WallaseaIsland where a major flood defence project is being fed by 4.5m tonnes of Crossrail excavations, creating Europe's largest man-made nature reserve.

Above the cacophany our tour guides, all project engineers, attempted to explain what was going on below ground. Last month tunnelling machine Elizabeth arrived at Whitechapel after drilling through from Canning Town, but has to pause awhile because no drilling is currently allowed beneath the existing Overground platforms. Various linking tunnels are being dug to link the eastbound and westbound railway - some as linking passages and concourses for passengers, a couple for trains passing from one line to the other. Subterranean surfaces are being strengthened and sprayed to withstand a lifetime of stresses. A team of 40 people work around the clock on the Cambridge Heath shaft, to bring this small part of the massive project to fruition. And a temporary rear entrance to Whitechapel station is being prepared, which all passengers will have to start using maybe as early as next month.

After our half hour was up we walked back round the the edge of the shaft and stepped outside. There was no glossy film to watch, no printed promotional material to take away, just thanks and a request to take off our safety gear. It did seem somewhat surreal returning so swiftly to retail reality, immediately outside the entrance to the supermarket, as local people carried their Sunday shopping home entirely oblivious to the huge hole beyond the hoardings. But then you never do know what might be lurking in a Sainsbury's car park. And when the new railway does finally open, you'll probably not give another thought to the vast shaft overhead ventilating your journey.